UBSan: Add blacklist files for WebRTC standalone.

tools/ubsan/vptr_blacklist.txt

Index: tools/ubsan/vptr_blacklist.txt
diff --git a/tools/ubsan/vptr_blacklist.txt b/tools/ubsan/vptr_blacklist.txt
new file mode 100644
index 0000000000000000000000000000000000000000..02adc84630cd46b4c1578d3590791a62d0969f49
--- /dev/null
+++ b/tools/ubsan/vptr_blacklist.txt
@@ -0,0 +1,22 @@
+#############################################################################
+# UBSan vptr blacklist.
+# Function and type based blacklisting use a mangled name, and it is especially
+# tricky to represent C++ types. For now, any possible changes by name manglings
+# are simply represented as wildcard expressions of regexp, and thus it might be
+# over-blacklisted.
+#
+# Please think twice before you add or remove these rules.
+#
+# This is a stripped down copy of Chromium's vptr_blacklist.txt, to enable
+# adding WebRTC-specific blacklist entries.
+
+#############################################################################
+# Using raw pointer values.
+#
+# A raw pointer value (16) is used to infer the field offset by
+# GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET.
+
+src:*/third_party/protobuf/src/google/protobuf/compiler/plugin.pb.cc
+src:*/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_message.cc
+src:*/third_party/protobuf/src/google/protobuf/descriptor.pb.cc
+